/*============================================================================
 * Handle export of mesh and fields.
 *============================================================================*/

/*
  This file is part of code_saturne, a general-purpose CFD tool.

  Copyright (C) 1998-2025 EDF S.A.

  This program is free software; you can redistribute it and/or modify it under
  the terms of the GNU General Public License as published by the Free Software
  Foundation; either version 2 of the License, or (at your option) any later
  version.

  This program is distributed in the hope that it will be useful, but WITHOUT
  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  details.

  You should have received a copy of the GNU General Public License along with
  this program; if not, write to the Free Software Foundation, Inc., 51 Franklin
  Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/

/*----------------------------------------------------------------------------*/

#include "base/cs_defs.h"

/*----------------------------------------------------------------------------
 * Standard C library headers
 *----------------------------------------------------------------------------*/

#include <assert.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#if defined(HAVE_DLOPEN)
#include <dlfcn.h>
#endif

/*----------------------------------------------------------------------------
 *  Local headers
 *----------------------------------------------------------------------------*/

#include "bft/bft_error.h"
#include "bft/bft_printf.h"

#include "fvm/fvm_nodal.h"
#include "fvm/fvm_nodal_priv.h"

#include "base/cs_base.h"
#include "base/cs_file.h"
#include "base/cs_fp_exception.h"
#include "base/cs_mem.h"
#include "base/cs_timer.h"

/*----------------------------------------------------------------------------
 *  Header for the current file
 *----------------------------------------------------------------------------*/

#include "fvm/fvm_writer.h"
#include "fvm/fvm_writer_priv.h"

/* Headers for available writers (could be replaced by plugin system) */

#include "fvm/fvm_to_ccm.h"
#include "fvm/fvm_to_cgns.h"
#include "fvm/fvm_to_med.h"
#include "fvm/fvm_to_ensight.h"
#include "fvm/fvm_to_histogram.h"
#include "fvm/fvm_to_plot.h"
#include "fvm/fvm_to_time_plot.h"

#if defined(HAVE_CATALYST) && !defined(HAVE_PLUGIN_CATALYST)
#include "fvm/fvm_to_catalyst.h"
#endif

#if defined(HAVE_CATALYST2) && !defined(HAVE_PLUGIN_CATALYST2)
#include "fvm_to_catalyst2.h"
#endif

#if defined(HAVE_MELISSA) && !defined(HAVE_PLUGIN_MELISSA)
#include "fvm/fvm_to_melissa.h"
#endif

/*----------------------------------------------------------------------------*/

BEGIN_C_DECLS

/*! \cond DOXYGEN_SHOULD_SKIP_THIS */

/*============================================================================
 * Local Type Definitions
 *============================================================================*/

/*============================================================================
 * Local macro definitions
 *============================================================================*/

/* Directory name separator
   (historically, '/' for Unix/Linux, '\' for Windows, ':' for Mac
   but '/' should work for all on modern systems) */

#define DIR_SEPARATOR '/'

/*============================================================================
 * Static and constant variables
 *============================================================================*/

/* Number and status of defined formats */

static const int _fvm_writer_n_formats = 11;

static fvm_writer_format_t _fvm_writer_format_list[11] = {

  /* Built-in EnSight Gold writer */
  {
    "EnSight Gold",
    "7.4 +",
    (  FVM_WRITER_FORMAT_HAS_POLYGON
     | FVM_WRITER_FORMAT_HAS_POLYHEDRON),
    FVM_WRITER_TRANSIENT_CONNECT,
    0,                                 /* dynamic library count */
    0,                                 /* dynamic library flags */
    nullptr,                              /* dynamic library */
    nullptr,                              /* dynamic library name */
    nullptr,                              /* dynamic library prefix */
    nullptr,                              /* n_version_strings_func */
    nullptr,                              /* version_string_func */
    fvm_to_ensight_init_writer,        /* init_func */
    fvm_to_ensight_finalize_writer,    /* finalize_func */
    fvm_to_ensight_set_mesh_time,      /* set_mesh_time_func */
    fvm_to_ensight_needs_tesselation,  /* needs_tesselation_func */
    fvm_to_ensight_export_nodal,       /* export_nodal_func */
    fvm_to_ensight_export_field,       /* export_field_func */
    nullptr                               /* flush_func */
  },

  /* MED writer */
  {
    "MED",
    "3.0 +",
    (  FVM_WRITER_FORMAT_USE_EXTERNAL
     | FVM_WRITER_FORMAT_HAS_POLYGON
     | FVM_WRITER_FORMAT_HAS_POLYHEDRON),
    FVM_WRITER_FIXED_MESH,
    0,                                 /* dynamic library count */
    0,                                 /* dynamic library flags */
    nullptr,                              /* dynamic library */
    nullptr,                              /* dynamic library name */
    nullptr,                              /* dynamic library prefix */
#if defined(HAVE_MED)
    fvm_to_med_n_version_strings,      /* n_version_strings_func */
    fvm_to_med_version_string,         /* version_string_func */
    fvm_to_med_init_writer,            /* init_func */
    fvm_to_med_finalize_writer,        /* finalize_func */
    fvm_to_med_set_mesh_time,          /* set_mesh_time_func */
    fvm_to_med_needs_tesselation,      /* needs_tesselation_func */
    fvm_to_med_export_nodal,           /* export_nodal_func */
    fvm_to_med_export_field,           /* export_field_func */
    nullptr                               /* flush_func */
#else
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr
#endif
  },

  /* CGNS writer */
  {
    "CGNS",
    "3.1 +",
    (  FVM_WRITER_FORMAT_USE_EXTERNAL
     | FVM_WRITER_FORMAT_HAS_POLYGON),
    FVM_WRITER_TRANSIENT_COORDS,
    0,                                 /* dynamic library count */
    0,                                 /* dynamic library flags */
    nullptr,                              /* dynamic library */
    nullptr,                              /* dynamic library name */
    nullptr,                              /* dynamic library prefix */
#if defined(HAVE_CGNS)
    fvm_to_cgns_n_version_strings,     /* n_version_strings_func */
    fvm_to_cgns_version_string,        /* version_string_func */
    fvm_to_cgns_init_writer,           /* init_func */
    fvm_to_cgns_finalize_writer,       /* finalize_func */
    fvm_to_cgns_set_mesh_time,         /* set_mesh_time_func */
    fvm_to_cgns_needs_tesselation,     /* needs_tesselation_func */
    fvm_to_cgns_export_nodal,          /* export_nodal_func */
    fvm_to_cgns_export_field,          /* export_field_func */
    nullptr                               /* flush_func */
#else
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr
#endif
  },

  /* Catalyst2 writer */
  {
    "Catalyst2",
    "ParaView 5.11 +",
    (  FVM_WRITER_FORMAT_USE_EXTERNAL
     | FVM_WRITER_FORMAT_HAS_POLYGON
     | FVM_WRITER_FORMAT_HAS_POLYHEDRON
     | FVM_WRITER_FORMAT_NO_SEPARATE_MESHES),
    FVM_WRITER_TRANSIENT_CONNECT,
#if !defined(HAVE_CATALYST2) || defined(HAVE_PLUGIN_CATALYST2)
    0,                                 /* dynamic library count */
    0,                                 /* dynamic library flags */
    NULL,                              /* dynamic library */
#if defined(HAVE_CATALYST2)
    "fvm_catalyst2",                   /* dynamic library name */
    "fvm_to_catalyst2_",               /* dynamic library prefix */
#else
    NULL,
    NULL,
#endif
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL
#else
    0,                                 /* dynamic library count */
    0,                                 /* dynamic library flags */
    NULL,                              /* dynamic library */
    NULL,                              /* dynamic library name */
    NULL,                              /* dynamic library prefix */
    fvm_to_catalyst2_n_version_strings, /* n_version_strings_func */
    fvm_to_catalyst2_version_string,   /* version_string_func */
    fvm_to_catalyst2_init_writer,      /* init_func */
    fvm_to_catalyst2_finalize_writer,  /* finalize_func */
    fvm_to_catalyst2_set_mesh_time,    /* set_mesh_time_func */
    NULL,                              /* needs_tesselation_func */
    fvm_to_catalyst2_export_nodal,     /* export_nodal_func */
    fvm_to_catalyst2_export_field,     /* export_field_func */
    fvm_to_catalyst2_flush             /* flush_func */
#endif
  },

  /* Catalyst (VTK) writer (plugin)

     On some systems, loading the Catalyst module as a plug-in (default)
     seems to interfere with the detection of required OpenGL2 features
     or extensions required by ParaView, or with other associated libraries
     (such as importing vtk libraries from Python on Debian 10 with
     a SALOME 9.10 CAS build of ParaView).
     Adding the RTLD_GLOBAL flag to dlopen seems to be sufficient to avoid
     these issues on current systems. */
  {
    "Catalyst",
    "5.4 +",
    (  FVM_WRITER_FORMAT_USE_EXTERNAL
     | FVM_WRITER_FORMAT_HAS_POLYGON
     | FVM_WRITER_FORMAT_HAS_POLYHEDRON
     | FVM_WRITER_FORMAT_NO_SEPARATE_MESHES),
    FVM_WRITER_TRANSIENT_CONNECT,
#if !defined(HAVE_CATALYST) || defined(HAVE_PLUGIN_CATALYST)
    0,                                 /* dynamic library count */
#  if defined(HAVE_DLOPEN)
    RTLD_LAZY | RTLD_GLOBAL,
#  else
    0,                                 /* dynamic library flags */
#  endif
    nullptr,                              /* dynamic library */
#if defined(HAVE_CATALYST)
    "fvm_catalyst",                    /* dynamic library name */
    "fvm_to_catalyst_",                /* dynamic library prefix */
#else
    nullptr,
    nullptr,
#endif
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr
#else
    0,                                 /* dynamic library count */
    0,                                 /* dynamic library flags */
    nullptr,                              /* dynamic library */
    nullptr,                              /* dynamic library name */
    nullptr,                              /* dynamic library prefix */
    nullptr,                              /* n_version_strings_func */
    nullptr,                              /* version_string_func */
    fvm_to_catalyst_init_writer,       /* init_func */
    fvm_to_catalyst_finalize_writer,   /* finalize_func */
    fvm_to_catalyst_set_mesh_time,     /* set_mesh_time_func */
    nullptr,                              /* needs_tesselation_func */
    fvm_to_catalyst_export_nodal,      /* export_nodal_func */
    fvm_to_catalyst_export_field,      /* export_field_func */
    fvm_to_catalyst_flush              /* flush_func */
#endif
  },

  /* MEDCoupling writer (plugin) */
  {
    "MEDCoupling",
    "6.3 +",
    (  FVM_WRITER_FORMAT_USE_EXTERNAL
     | FVM_WRITER_FORMAT_HAS_POLYGON),
    FVM_WRITER_TRANSIENT_CONNECT,
    0,                                 /* dynamic library count */
    0,                                 /* dynamic library flags */
    nullptr,                              /* dynamic library */
#if defined(HAVE_MEDCOUPLING)
    "fvm_medcoupling",                 /* dynamic library name */
    "fvm_to_medcoupling_",             /* dynamic library prefix */
#else
    nullptr,
    nullptr,
#endif
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr
  },

  /* Built-in Melissa writer */
  {
    "Melissa",
    "",
    (  FVM_WRITER_FORMAT_USE_EXTERNAL
     | FVM_WRITER_FORMAT_HAS_POLYGON
     | FVM_WRITER_FORMAT_HAS_POLYHEDRON),
    FVM_WRITER_TRANSIENT_COORDS,
#if !defined(HAVE_MELISSA) || defined(HAVE_PLUGIN_MELISSA)
    0,                                 /* dynamic library count */
    0,                                 /* dynamic library flags */
    nullptr,                              /* dynamic library */
#if defined(HAVE_MELISSA)
    "fvm_melissa",                     /* dynamic library name */
    "fvm_to_melissa_",                 /* dynamic library prefix */
#else
    nullptr,
    nullptr,
#endif
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr
#else
    0,                                 /* dynamic library count */
    0,                                 /* dynamic library flags */
    nullptr,                              /* dynamic library */
    nullptr,                              /* dynamic library name */
    nullptr,                              /* dynamic library prefix */
    nullptr,                              /* n_version_strings_func */
    nullptr,                              /* version_string_func */
    fvm_to_melissa_init_writer,        /* init_func */
    fvm_to_melissa_finalize_writer,    /* finalize_func */
    fvm_to_melissa_set_mesh_time,      /* set_mesh_time_func */
    nullptr,                              /* needs_tesselation_func */
    fvm_to_melissa_export_nodal,       /* export_nodal_func */
    fvm_to_melissa_export_field,       /* export_field_func */
    nullptr                               /* flush_func */
#endif
  },

  /* Built-in histogram writer */
  {
    "histogram",
    "",
    (  FVM_WRITER_FORMAT_HAS_POLYGON
     | FVM_WRITER_FORMAT_HAS_POLYHEDRON
     | FVM_WRITER_FORMAT_SEPARATE_MESHES
     | FVM_WRITER_FORMAT_NAME_IS_OPTIONAL),
       FVM_WRITER_TRANSIENT_CONNECT,
    0,                                 /* dynamic library count */
    0,                                 /* dynamic library flags */
    nullptr,                              /* dynamic library */
    nullptr,                              /* dynamic library name */
    nullptr,                              /* dynamic library prefix */
    nullptr,                              /* n_version_strings_func */
    nullptr,                              /* version_string_func */
    fvm_to_histogram_init_writer,      /* init_func */
    fvm_to_histogram_finalize_writer,  /* finalize_func */
    fvm_to_histogram_set_mesh_time,    /* set_mesh_time_func */
    nullptr,                              /* needs_tesselation_func */
    nullptr,                              /* export_nodal_func */
    fvm_to_histogram_export_field,     /* export_field_func */
    fvm_to_histogram_flush             /* flush_func */
  },

  /* Built-in plot writer */
  {
    "plot",
    "",
    (  FVM_WRITER_FORMAT_HAS_POLYGON
     | FVM_WRITER_FORMAT_HAS_POLYHEDRON
     | FVM_WRITER_FORMAT_SEPARATE_MESHES
     | FVM_WRITER_FORMAT_NAME_IS_OPTIONAL),
    FVM_WRITER_TRANSIENT_CONNECT,
    0,                                 /* dynamic library count */
    0,                                 /* dynamic library flags */
    nullptr,                              /* dynamic library */
    nullptr,                              /* dynamic library name */
    nullptr,                              /* dynamic library prefix */
    nullptr,                              /* n_version_strings_func */
    nullptr,                              /* version_string_func */
    fvm_to_plot_init_writer,           /* init_func */
    fvm_to_plot_finalize_writer,       /* finalize_func */
    fvm_to_plot_set_mesh_time,         /* set_mesh_time_func */
    nullptr,                              /* needs_tesselation_func */
    fvm_to_plot_export_nodal,          /* export_nodal_func */
    fvm_to_plot_export_field,          /* export_field_func */
    fvm_to_plot_flush                  /* flush_func */
  },

  /* Built-in time plot writer */
  {
    "time_plot",
    "",
    (  FVM_WRITER_FORMAT_HAS_POLYGON
     | FVM_WRITER_FORMAT_HAS_POLYHEDRON
     | FVM_WRITER_FORMAT_SEPARATE_MESHES
     | FVM_WRITER_FORMAT_NAME_IS_OPTIONAL),
    FVM_WRITER_FIXED_MESH,
    0,                                 /* dynamic library count */
    0,                                 /* dynamic library flags */
    nullptr,                              /* dynamic library */
    nullptr,                              /* dynamic library name */
    nullptr,                              /* dynamic library prefix */
    nullptr,                              /* n_version_strings_func */
    nullptr,                              /* version_string_func */
    fvm_to_time_plot_init_writer,      /* init_func */
    fvm_to_time_plot_finalize_writer,  /* finalize_func */
    fvm_to_time_plot_set_mesh_time,    /* set_mesh_time_func */
    nullptr,                              /* needs_tesselation_func */
    fvm_to_time_plot_export_nodal,     /* export_nodal_func */
    fvm_to_time_plot_export_field,     /* export_field_func */
    nullptr                               /* flush_func */
  },

  /* CCM-IO writer */
  {
    "CCM-IO",
    "2.6.1+",
    (  FVM_WRITER_FORMAT_USE_EXTERNAL
     | FVM_WRITER_FORMAT_HAS_POLYGON
     | FVM_WRITER_FORMAT_HAS_POLYHEDRON),
    FVM_WRITER_FIXED_MESH,
    0,                                 /* dynamic library count */
    0,                                 /* dynamic library flags */
    nullptr,                              /* dynamic library */
    nullptr,                              /* dynamic library name */
    nullptr,                              /* dynamic library prefix */
#if defined(HAVE_CCM)
    fvm_to_ccm_n_version_strings,     /* n_version_strings_func */
    fvm_to_ccm_version_string,        /* version_string_func */
    fvm_to_ccm_init_writer,           /* init_func */
    fvm_to_ccm_finalize_writer,       /* finalize_func */
    fvm_to_ccm_set_mesh_time,         /* set_mesh_time_func */
    nullptr,                             /* needs_tesselation_func */
    fvm_to_ccm_export_nodal,          /* export_nodal_func */
    fvm_to_ccm_export_field,          /* export_field_func */
    nullptr                               /* flush_func */
#else
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    nullptr
#endif
  }

};

/*! (DOXYGEN_SHOULD_SKIP_THIS) \endcond */

/*============================================================================
 * Static global variables
 *============================================================================*/

/* Names of time dependency enumeration values */

const char  *fvm_writer_time_dep_name[] = {N_("fixed mesh"),
                                           N_("transient coordinates"),
                                           N_("transient connectivity")};

const char _empty_string[] = "";

/*! \cond DOXYGEN_SHOULD_SKIP_THIS */

/*============================================================================
 * Private function definitions
 *============================================================================*/

/*----------------------------------------------------------------------------
 * Transform a string containing a list of options to lowercase with
 * whitespace separators.
 * The new list is dynamically allocated, and should be freed when no
 * longer needed.
 *
 * parameters:
 *   option_list <-- options string (case-independent, whitespace,
 *                   semicolon, or comma separated list)
 *
 * returns:
 *   single-whitespace separated option string in lowercase.
 *----------------------------------------------------------------------------*/

static char *
_fvm_writer_option_list(const char  *const option_list)
{
  char *ret_list;
  int i, j, l;

  if (option_list == nullptr)
    return nullptr;

  l = strlen(option_list);

  CS_MALLOC(ret_list, l + 1, char);

  /* Transform format name to lowercase, single whitespace separated */

  for (i = 0, j = 0 ; i < l ; i++) {
    ret_list[j] = tolower(option_list[i]);
    if (ret_list[j] == ',' || ret_list[j] == ';' || ret_list[j] == '\t')
      ret_list[j] = ' ';
    if (ret_list[j] != ' ' || (j > 0 && ret_list[j-1] != ' '))
      j++;
  }
  if (j > 0 && ret_list[j-1] == ' ')
    j--;

  ret_list[j] = '\0';

  return ret_list;
}

#if defined(HAVE_DLOPEN)

/*----------------------------------------------------------------------------
 * Get a shared library function pointer for a writer plugin
 *
 * parameters:
 *   wf               <-- pointer to writer format structure
 *   name             <-- name of function symbol in library
 *   errors_are_fatal <-- abort if true, silently ignore if false
 *
 * returns:
 *   pointer to function in shared library
 *----------------------------------------------------------------------------*/

static void *
_get_dl_function_pointer(fvm_writer_format_t  *wf,
                         const char           *name,
                         bool                  errors_are_fatal)
{
  void  *retval = nullptr;

  assert(wf != nullptr);
  assert(wf->dl_lib != nullptr);

  if (wf->dl_name == nullptr)
    retval = cs_base_get_dl_function_pointer(wf->dl_lib,
                                             name,
                                             errors_are_fatal);
  else {
    char *_name;
    CS_MALLOC(_name, strlen(wf->dl_prefix) + strlen(name) + 1, char);
    sprintf(_name, "%s%s", wf->dl_prefix, name);
    retval = cs_base_get_dl_function_pointer(wf->dl_lib,
                                             _name,
                                             errors_are_fatal);
    CS_FREE(_name);
  }

  return retval;
}

/*----------------------------------------------------------------------------
 * Load Plugin writer.
 *
 * parameters:
 *   wf <-> pointer to library format writer.
 *----------------------------------------------------------------------------*/

static void
_load_plugin(fvm_writer_format_t  *wf)
{
  /* Open from shared library */

  int flags_save = 0;

  if (wf->dl_flags != 0) {
    flags_save = cs_base_dlopen_get_flags();
    cs_base_dlopen_set_flags(wf->dl_flags);
  }

  wf->dl_lib = cs_base_dlopen_plugin(wf->dl_name);

  if (wf->dl_flags != 0) {
    cs_base_dlopen_set_flags(flags_save);
  }

  /* Increment reference count */

  wf->dl_count += 1;

  /* Load symbols from shared library */

  /* Function pointers need to be double-casted so as to first convert
     a (void *) type to a memory address and then convert it back to the
     original type. Otherwise, the compiler may issue a warning.
     This is a valid ISO C construction. */

  wf->n_version_strings_func = (fvm_writer_n_version_strings_t *) (intptr_t)
    _get_dl_function_pointer(wf, "n_version_strings", false);

  wf->version_string_func = (fvm_writer_version_string_t *) (intptr_t)
    _get_dl_function_pointer(wf, "version_string", false);

  wf->init_func = (fvm_writer_init_t *) (intptr_t)
    _get_dl_function_pointer(wf, "init_writer", true);

  wf->finalize_func = (fvm_writer_finalize_t *) (intptr_t)
    _get_dl_function_pointer(wf, "finalize_writer", true);

  wf->set_mesh_time_func = (fvm_writer_set_mesh_time_t *) (intptr_t)
    _get_dl_function_pointer(wf, "set_mesh_time", true);

  wf->needs_tesselation_func = (fvm_writer_needs_tesselation_t *) (intptr_t)
    _get_dl_function_pointer(wf, "needs_tesselation", false);

  wf->export_nodal_func = (fvm_writer_export_nodal_t *) (intptr_t)
    _get_dl_function_pointer(wf, "export_nodal", true);

  wf->export_field_func = (fvm_writer_export_field_t *) (intptr_t)
    _get_dl_function_pointer(wf, "export_field", true);

  wf->flush_func = (fvm_writer_flush_t *) (intptr_t)
    _get_dl_function_pointer(wf, "flush", false);
}

/*----------------------------------------------------------------------------
 * Unload Plugin writer.
 *
 * parameters:
 *   wf <-> pointer to library format writer.
 *----------------------------------------------------------------------------*/

static void
_close_plugin(fvm_writer_format_t  *wf)
{
  /* Open from shared library */

  if (wf->dl_lib == nullptr)
    return;

  cs_base_dlclose(wf->name, wf->dl_lib);

  wf->dl_lib = nullptr;

  /* Decrement reference count */

  wf->dl_count -= 1;

  /* Reset pointers */

  if (wf->dl_count == 0) {
    wf->n_version_strings_func = nullptr;
    wf->version_string_func = nullptr;
    wf->init_func = nullptr;
    wf->finalize_func = nullptr;
    wf->set_mesh_time_func = nullptr;
    wf->needs_tesselation_func = nullptr;
    wf->export_nodal_func = nullptr;
    wf->export_field_func = nullptr;
    wf->flush_func = nullptr;
  }
}

#endif /* defined(HAVE_DLOPEN)*/

/*----------------------------------------------------------------------------
 * Initialize specific format writer based on writer and optional
 * mesh name info.
 *
 * parameters:
 *   this_writer     <-- pointer to mesh and field output writer
 *   mesh_name       <-- optional mesh name, or nullptr
 *
 * returns:
 *   pointer to mesh and field output writer
 *----------------------------------------------------------------------------*/

static void *
_format_writer_init(fvm_writer_t  *this_writer,
                    const char    *mesh_name)
{
  const  char empty[] = "";
  const  char untitled[] = "[untitled]";

  char   local_dir[] = ".";
  char  *tmp_path = nullptr, *tmp_name = nullptr;

  void  *format_writer = nullptr;

  /* Determine path and create directory if needed */

  const char *path = local_dir;

  if (this_writer->path != nullptr) {

    int l = strlen(this_writer->path);

    if (l > 0) {
      CS_MALLOC(tmp_path, l + 2, char);
      strcpy(tmp_path, this_writer->path);
      if (tmp_path[l - 1] == DIR_SEPARATOR)
        tmp_path[l - 1] = '\0';
      int dir_err = 0;
      if (cs_glob_rank_id < 1)
        dir_err = cs_file_mkdir_default(this_writer->path);
#if defined(HAVE_MPI)
      if (cs_glob_n_ranks > 1)
        MPI_Bcast(&dir_err, 1, MPI_INT, 0, cs_glob_mpi_comm);
#endif
      if (dir_err == 1)
        tmp_path[0] = '\0';
      else {
        l = strlen(tmp_path);
        tmp_path[l]   = DIR_SEPARATOR;
        tmp_path[l+1] = '\0';
      }
      path = tmp_path;
    }

  }

  const char *name = this_writer->name;

  if (name != nullptr) {
    size_t lw = strlen(this_writer->name);
    if (lw == 0)
      name = mesh_name;
    else if (mesh_name != nullptr) {
      if (strlen(mesh_name) > 0) {
        size_t l = lw + 1 + strlen(mesh_name);
        CS_MALLOC(tmp_name, l + 1, char);
        sprintf(tmp_name, "%s_%s", this_writer->name, mesh_name);
        for (size_t i = lw + 1, j = 0; i < l; i++, j++) {
          if (tmp_name[i] == ' ')
            tmp_name[i] = '_';
        }
        name = tmp_name;
      }
    }
  }
  else
    name = mesh_name;

  if (name == nullptr) {
    if (this_writer->format->info_mask & FVM_WRITER_FORMAT_NAME_IS_OPTIONAL)
      name = empty;
    else
      name = untitled;
  }

  /* Initialize format-specific writer */

  fvm_writer_init_t  *init_func = this_writer->format->init_func;

  if (init_func != nullptr) {

    cs_fp_exception_disable_trap();

#if defined(HAVE_MPI)
    format_writer = init_func(name,
                              path,
                              this_writer->options,
                              this_writer->time_dep,
                              cs_glob_mpi_comm);
#else
    format_writer = init_func(name,
                              path,
                              this_writer->options,
                              this_writer->time_dep);
#endif

    cs_fp_exception_restore_trap();

  }

  CS_FREE(tmp_name);
  CS_FREE(tmp_path);

  /* Return pointer to initialized writer */

  return format_writer;
}

/*----------------------------------------------------------------------------
 * Find or add a specific format writer based on writer and optional
 * mesh name info.
 *
 * parameters:
 *   this_writer     <-- pointer to mesh and field output writer
 *   mesh_name       <-- optional mesh name, or nullptr
 *
 * returns:
 *   pointer to mesh and field output writer
 *----------------------------------------------------------------------------*/

static void*
_find_or_add_format_writer(fvm_writer_t        *this_writer,
                           const fvm_nodal_t   *mesh)
{
  void  *format_writer = nullptr;

  assert(this_writer != nullptr);
  assert(this_writer->format != nullptr);

  /* Find or add single-mesh writer if required */

  if  (   this_writer->n_format_writers == 0
       || this_writer->mesh_names != nullptr) {
    int i;
    const char empty[] = "";
    const char *name = (mesh->name != nullptr) ? mesh->name : empty;
    for (i = 0; i < this_writer->n_format_writers; i++) {
      if (strcmp(this_writer->mesh_names[i], name) == 0)
        break;
    }
    if (i >= this_writer->n_format_writers) {
      CS_REALLOC(this_writer->format_writer, i + 1, void *);
      CS_REALLOC(this_writer->mesh_names, i + 1, char *);
      CS_MALLOC(this_writer->mesh_names[i], strlen(name) + 1, char);
      strcpy(this_writer->mesh_names[i], name);
      this_writer->format_writer[i] = _format_writer_init(this_writer, name);
      this_writer->n_format_writers += 1;
    }
    format_writer = this_writer->format_writer[i];
  }
  else
    format_writer = this_writer->format_writer[0];

  return format_writer;
}

/*============================================================================
 * Semi-private function definitions (prototypes in "fvm/fvm_writer_priv.h)
 *============================================================================*/

/*! (DOXYGEN_SHOULD_SKIP_THIS) \endcond */

/*============================================================================
 * Public function definitions
 *============================================================================*/

/*----------------------------------------------------------------------------
 * Find the format matching a name,
 *
 * parameters:
 *   format_name <-- name of desired format
 *
 * returns:
 *   index of the format matching the given name, or -1 if none matches.
 *----------------------------------------------------------------------------*/

int
fvm_writer_get_format_id(const char  *format_name)
{
  char  tmp_name[32], closest_name[32];
  int i, l;

  if (format_name == nullptr)
    return _fvm_writer_n_formats;

  l = strlen(format_name);

  /* Transform format name to lowercase, whitespace as underscore */

  strncpy(tmp_name, format_name, 32);
  tmp_name[31] = '\0';
  for (i = 0 ; i < l ; i++) {
    tmp_name[i] = tolower(tmp_name[i]);
    if (tmp_name[i] == ' ' || tmp_name[i] == '\t')
      tmp_name[i] = '_';
  }

  /* Try "known" names */

  if (strncmp(tmp_name, "ensight", 7) == 0)
    strcpy(closest_name, "EnSight Gold");
  else if (strncmp(tmp_name, "medcoupling", 11) == 0)
    strcpy(closest_name, "MEDCoupling");
  else if (strncmp(tmp_name, "med", 3) == 0)
    strcpy(closest_name, "MED");
  else if (strncmp(tmp_name, "cgns", 4) == 0)
    strcpy(closest_name, "CGNS");
  else if (strncmp(tmp_name, "catalyst", 8) == 0) {
    strcpy(closest_name, "Catalyst");

    /* If both Catalyst2 is available, prefer if to the legacy implmentation
       by default, and extend the use of the CATALYST_IMPLEMENTATION_NAME
       environment logic to allow reverting to the legacy implementation. */
#   if defined(HAVE_CATALYST2)
    strcpy(closest_name, "Catalyst2");
    const char *s = getenv("CATALYST_IMPLEMENTATION_NAME");
    if (s != nullptr) {
      if (strcmp(s, "legacy") == 0)
        strcpy(closest_name, "Catalyst");
    }
#   endif
  }
  else if (strncmp(tmp_name, "ccm", 3) == 0)
    strcpy(closest_name, "CCM-IO");
  else if (strncmp(tmp_name, "melissa", 7) == 0)
    strcpy(closest_name, "Melissa");
  else
    strcpy(closest_name, tmp_name);

  /* Find name in list */

  for (i = 0 ; i < _fvm_writer_n_formats ; i++)
    if (strcmp(closest_name, _fvm_writer_format_list[i].name) == 0)
      break;

  return i;
}

/*----------------------------------------------------------------------------
 * Returns number of known formats.
 *----------------------------------------------------------------------------*/

int
fvm_writer_n_formats(void)
{
  return _fvm_writer_n_formats;
}

/*----------------------------------------------------------------------------
 * Returns name of a known format.
 *
 * parameters:
 *   format_index <-- index of format in known format list (0 to n-1)
 *
 * returns:
 *   pointer to constant string containing the format's name
 *----------------------------------------------------------------------------*/

const char *
fvm_writer_format_name(int format_index)
{
  if (format_index >= 0 && format_index < _fvm_writer_n_formats)
    return _fvm_writer_format_list[format_index].name;

  else
    return nullptr;
}

/*----------------------------------------------------------------------------
 * Returns availability of a known format.
 *
 * parameters:
 *   format_index <-- index of format in known format list (0 to n-1)
 *
 * returns:
 *   1 if the format is available, 0 otherwise.
 *----------------------------------------------------------------------------*/

int
fvm_writer_format_available(int format_index)
{
  int retval = 0;

  if (format_index >= 0 && format_index < _fvm_writer_n_formats) {

    if (_fvm_writer_format_list[format_index].init_func != nullptr)
      retval = 1;

#if defined(HAVE_DLOPEN)
    else if (_fvm_writer_format_list[format_index].dl_name != nullptr)
      retval = 1;
#endif

  }
  return retval;
}

/*----------------------------------------------------------------------------
 * Returns number of library version strings associated with a given format.
 *
 * For writers requiring an external library, the first associated
 * version string should correspond to that library, with possible
 * additional version strings for its dependencies.
 *
 * For writers only requiring standard libraries (libc, MPI, MPI-IO),
 * this function should return 0.
 *
 * parameters:
 *   format_index <-- index of format in known format list (0 to n-1)
 *
 * returns:
 *   number of library version strings associated with a given format.
 *----------------------------------------------------------------------------*/

int
fvm_writer_n_version_strings(int format_index)
{
  int retval = 0;
  fvm_writer_n_version_strings_t  *n_version_strings_func = nullptr;

  if (format_index >= 0 && format_index < _fvm_writer_n_formats) {
    n_version_strings_func
      = _fvm_writer_format_list[format_index].n_version_strings_func;
    if (n_version_strings_func != nullptr)
      retval = n_version_strings_func();
  }
  return retval;
}

/*----------------------------------------------------------------------------
 * Returns a library version string associated with a given format.
 *
 * We must have string_index < fvm_writer_n_version_strings(format_index).
 *
 * In certain cases, when using dynamic libraries, fvm may be compiled
 * with one library version, and linked with another. If both run-time
 * and compile-time version information is available, this function
 * will return the run-time version string by default.
 *
 * Setting the compile_time flag to 1, the compile-time version string
 * will be returned if this is different from the run-time version.
 * If the version is the same, or only one of the 2 version strings are
 * available, a nullptr character string will be returned with this flag set.
 *
 * parameters:
 *   format_index <-- index of format in known format list (0 to n-1)
 *   string_index <-- index in format's version string list (0 to n-1)
 *   compile_time <-- 0 by default, 1 if we want the compile-time version
 *                    string, if different from the run-time version.
 *
 * returns:
 *   pointer to constant string containing the library's version.
 *----------------------------------------------------------------------------*/

const char *
fvm_writer_version_string(int format_index,
                          int string_index,
                          int compile_time_version)
{
  const char * retval = nullptr;
  fvm_writer_version_string_t  *version_string_func = nullptr;

  if (format_index >= 0 && format_index < _fvm_writer_n_formats) {
    version_string_func
      = _fvm_writer_format_list[format_index].version_string_func;
    if (version_string_func != nullptr)
      retval = version_string_func(string_index,
                                   compile_time_version);
  }
  return retval;
}

/*----------------------------------------------------------------------------
 * Remove a given option from a format options list if present.
 *
 * The possible separators are also transformed to whitespace and merged.
 *
 * parameters:
 *   format_options  <-> options for the selected format (case-independent,
 *                       whitespace or comma separated list)
 *   exclude_option  <-- option to be excluded
 *----------------------------------------------------------------------------*/

void
fvm_writer_filter_option(char        *format_options,
                         const char  *exclude_option)
{
  char  *tmp_options = nullptr;

  size_t l = strlen(exclude_option);

  /* Find corresponding format and check coherency */

  tmp_options = _fvm_writer_option_list(format_options);

  /* Parse top-level options (consuming those handled here);
     the options string now contains options separated by a single
     whitespace. */

  if (tmp_options != nullptr) {

    int i0 = 0, i1;

    while (tmp_options[i0] != '\0') {

      for (i1 = i0; tmp_options[i1] != '\0' && tmp_options[i1] != ' '; i1++);
      size_t l_opt = i1 - i0;

      if (   (l_opt == l)
          && (strncmp(tmp_options + i0, exclude_option, l_opt) == 0)) {
        if (tmp_options[i1] == ' ')
          strcpy(tmp_options + i0, tmp_options + i1 + 1);
        else {
          if (i0 > 1) {
            assert(tmp_options[i0-1] == ' ');
            i0--;
          }
          tmp_options[i0] = '\0';
        }
      }
      else {
        i0 = i1;
        if (tmp_options[i0] == ' ')
          i0++;
      }

      i1 = strlen(tmp_options);
      CS_REALLOC(tmp_options, i1+1, char);

    }

  }

  strcpy(format_options, tmp_options);

  CS_FREE(tmp_options);
}

/*----------------------------------------------------------------------------
 * Initialize FVM mesh and field output writer.
 *
 * Allowed options depend on what is applicable to a given format. Those
 * not relevant to a given writer are ignored. Possible options include:
 *   text                output text files
 *   binary              output binary files (default)
 *   big_endian          force binary files to big-endian
 *   discard_polygons    do not output polygons or related values
 *   discard_polyhedra   do not output polyhedra or related values
 *   divide_polygons     tesselate polygons with triangles
 *   divide_polyhedra    tesselate polyhedra with tetrahedra and pyramids
 *                       (adding a vertex near each polyhedron's center)
 *   separate_meshes     use a different writer for each mesh
 *
 * parameters:
 *   name            <-- base name of output
 *   path            <-- optional directory name for output
 *                       (directory automatically created if necessary)
 *   format_name     <-- name of selected format (case-independent)
 *   format_options  <-- options for the selected format (case-independent,
 *                       whitespace or comma separated list)
 *   time_dependency <-- indicates if and how meshes will change with time
 *
 * returns:
 *   pointer to mesh and field output writer
 *----------------------------------------------------------------------------*/

fvm_writer_t *
fvm_writer_init(const char             *name,
                const char             *path,
                const char             *format_name,
                const char             *format_options,
                fvm_writer_time_dep_t   time_dependency)
{
  int  i;
  char  *tmp_options = nullptr;
  fvm_writer_t  *this_writer = nullptr;
  bool separate_meshes = false;

  /* Find corresponding format and check coherency */

  for (i = 0 ; i < _fvm_writer_n_formats ; i++)
    if (strcmp(format_name, _fvm_writer_format_list[i].name) == 0)
      break;

  if (i >= _fvm_writer_n_formats)
    i = fvm_writer_get_format_id(format_name);

  if (i < 0)
    bft_error(__FILE__, __LINE__, 0,
              _("Format type \"%s\" required for case \"%s\" is unknown"),
              format_name, name);

  if (!fvm_writer_format_available(i))
    bft_error(__FILE__, __LINE__, 0,
              _("Format type \"%s\" required for case \"%s\" is not available"),
              format_name, name);

  tmp_options = _fvm_writer_option_list(format_options);

  /* Parse top-level options (consuming those handled here);
     the options string now contains options separated by a single
     whitespace. */

  if (tmp_options != nullptr) {

    int i0 = 0, i1;

    while (tmp_options[i0] != '\0') {

      for (i1 = i0; tmp_options[i1] != '\0' && tmp_options[i1] != ' '; i1++);
      int l_opt = i1 - i0;

      if (   (l_opt == 15)
          && (strncmp(tmp_options + i0, "separate_meshes", l_opt) == 0)) {
        separate_meshes = true;
        if (tmp_options[i1] == ' ')
          strcpy(tmp_options + i0, tmp_options + i1 + 1);
        else {
          if (i0 > 1) {
            assert(tmp_options[i0-1] == ' ');
            i0--;
          }
          tmp_options[i0] = '\0';
        }
      }
      else {
        i0 = i1;
        if (tmp_options[i0] == ' ')
          i0++;
      }

      i1 = strlen(tmp_options);
      if (i1 > 0)
        CS_REALLOC(tmp_options, i1+1, char);
      else {
        CS_FREE(tmp_options);
        break;
      }

    }

  }

  /* Initialize writer */

  CS_MALLOC(this_writer, 1, fvm_writer_t);

  CS_MALLOC(this_writer->name, strlen(name) + 1, char);
  strcpy(this_writer->name, name);

  this_writer->format = &(_fvm_writer_format_list[i]);

  /* Load plugin if required */

#if defined(HAVE_DLOPEN)
  if (this_writer->format->dl_name != nullptr)
    _load_plugin(this_writer->format);
#endif

  if (path) {
    CS_MALLOC(this_writer->path, strlen(path) + 1, char);
    strcpy(this_writer->path, path);
  }
  else
    this_writer->path = nullptr;

  this_writer->options = tmp_options;
  tmp_options = nullptr;

  this_writer->time_dep = cs::min(time_dependency,
                                  this_writer->format->max_time_dep);

  CS_TIMER_COUNTER_INIT(this_writer->mesh_time);
  CS_TIMER_COUNTER_INIT(this_writer->field_time);
  CS_TIMER_COUNTER_INIT(this_writer->flush_time);

  if (this_writer->format->info_mask & FVM_WRITER_FORMAT_SEPARATE_MESHES)
    separate_meshes = true;
  else if (  this_writer->format->info_mask
           & FVM_WRITER_FORMAT_NO_SEPARATE_MESHES)
    separate_meshes = false;

  if (separate_meshes)
    this_writer->n_format_writers = 0; /* Delay construction */
  else
    this_writer->n_format_writers = 1;

  this_writer->mesh_names = nullptr;

  /* Initialize format-specific writer */

  if  (this_writer->n_format_writers > 0) {
    CS_MALLOC(this_writer->format_writer, 1, void *);
    this_writer->format_writer[0] = _format_writer_init(this_writer,
                                                        nullptr);
  }
  else
    this_writer->format_writer = nullptr;

  /* Return pointer to initialized writer */

  return this_writer;
}

/*----------------------------------------------------------------------------
 * Finalize FVM mesh and field output writer.
 *
 * parameters:
 *   this_writer <-- pointer to mesh and field output writer
 *
 * returns:
 *   null pointer
 *----------------------------------------------------------------------------*/

fvm_writer_t *
fvm_writer_finalize(fvm_writer_t  *this_writer)
{
  fvm_writer_finalize_t  *finalize_func = nullptr;

  assert(this_writer != nullptr);
  assert(this_writer->format != nullptr);

  CS_FREE(this_writer->name);
  CS_FREE(this_writer->path);
  CS_FREE(this_writer->options);

  finalize_func = this_writer->format->finalize_func;

  if (finalize_func != nullptr) {
    cs_fp_exception_disable_trap();
    for (int i = 0; i < this_writer->n_format_writers; i++)
      finalize_func(this_writer->format_writer[i]);
    cs_fp_exception_restore_trap();
  }
  else
    this_writer->format_writer = nullptr;
  CS_FREE(this_writer->format_writer);

  if (this_writer->mesh_names != nullptr) {
    for (int i = 0; i < this_writer->n_format_writers; i++)
      CS_FREE(this_writer->mesh_names[i]);
  }
  CS_FREE(this_writer->mesh_names);

  /* Unload plugin if required */

#if defined(HAVE_DLOPEN)
  if (this_writer->format->dl_lib != nullptr)
    _close_plugin(this_writer->format);
#endif

  CS_FREE(this_writer);

  return nullptr;
}

/*----------------------------------------------------------------------------
 * Return a writer's name.
 *
 * parameters:
 *   this_writer <-- pointer to mesh and field output writer
 *
 * returns:
 *   pointer to base name of output associated with the writer
 *----------------------------------------------------------------------------*/

const char *
fvm_writer_get_name(const fvm_writer_t  *this_writer)
{
  return this_writer->name;
}

/*----------------------------------------------------------------------------
 * Return a writer's associated format name.
 *
 * parameters:
 *   this_writer <-- pointer to mesh and field output writer
 *
 * returns:
 *   pointer to output format name associated with the writer
 *----------------------------------------------------------------------------*/

const char *
fvm_writer_get_format(const fvm_writer_t  *this_writer)
{
  return this_writer->format->name;
}

/*----------------------------------------------------------------------------
 * Return a writer's associated format options.
 *
 * parameters:
 *   this_writer <-- pointer to mesh and field output writer
 *
 * returns:
 *   pointer to output format options associated with the writer
 *----------------------------------------------------------------------------*/

const char *
fvm_writer_get_options(const fvm_writer_t  *this_writer)
{
  const char *retval = _empty_string;
  if (this_writer->options != nullptr)
    retval = this_writer->options;
  return retval;
}

/*----------------------------------------------------------------------------
 * Return a writer's associated output directory.
 *
 * parameters:
 *   this_writer <-- pointer to mesh and field output writer
 *
 * returns:
 *   pointer to output format options associated with the writer
 *----------------------------------------------------------------------------*/

const char *
fvm_writer_get_path(const fvm_writer_t  *this_writer)
{
  const char *retval = _empty_string;
  if (this_writer->path != nullptr)
    retval = this_writer->path;
  return retval;
}

/*----------------------------------------------------------------------------
 * Return geometry time dependency status of a writer.
 *
 * parameters:
 *   this_writer <-- pointer to mesh and field output writer
 *
 * returns:
 *   time dependency status
 *----------------------------------------------------------------------------*/

fvm_writer_time_dep_t
fvm_writer_get_time_dep(const fvm_writer_t  *this_writer)
{
  return this_writer->time_dep;
}

/*----------------------------------------------------------------------------
 * Associate new time step with a mesh.
 *
 * parameters:
 *   this_writer_p <-- pointer to associated writer
 *   time_step     <-- time step number
 *   time_value    <-- time_value number
 *----------------------------------------------------------------------------*/

void
fvm_writer_set_mesh_time(fvm_writer_t  *this_writer,
                         int            time_step,
                         double         time_value)
{
  fvm_writer_set_mesh_time_t  *set_mesh_time_func = nullptr;

  assert(this_writer != nullptr);
  assert(this_writer->format != nullptr);

  set_mesh_time_func = this_writer->format->set_mesh_time_func;

  if (set_mesh_time_func != nullptr) {
    cs_fp_exception_disable_trap();
    for (int i = 0; i < this_writer->n_format_writers; i++)
      set_mesh_time_func(this_writer->format_writer[i],
                         time_step,
                         time_value);
    cs_fp_exception_restore_trap();
  }
}

/*----------------------------------------------------------------------------
 * Query if elements of a given type will need to be tesselated
 * for use of a nodal mesh with an output writer.
 *
 * This function should be called before any fvm_writer_export_...()
 *
 * parameters:
 *   this_writer  <-- pointer to mesh and field output writer
 *   mesh         <-- pointer to nodal mesh
 *   element_type <-- type of element
 *
 * returns:
 *   0 if no tesselation is necessary, 1 if tesselation is necessary.
 *----------------------------------------------------------------------------*/

int
fvm_writer_needs_tesselation(fvm_writer_t       *this_writer,
                             const fvm_nodal_t  *mesh,
                             fvm_element_t       element_type)
{
  int retval = 0;
  fvm_writer_needs_tesselation_t  *needs_tesselation_func = nullptr;

  void  *format_writer = _find_or_add_format_writer(this_writer, mesh);

  needs_tesselation_func = this_writer->format->needs_tesselation_func;
  if (needs_tesselation_func != nullptr)
    retval = needs_tesselation_func(format_writer,
                                    mesh,
                                    element_type);
  return retval;
}

/*----------------------------------------------------------------------------
 * Export FVM nodal mesh.
 *
 * parameters:
 *   this_writer <-- pointer to mesh and field output writer
 *   mesh        <-- pointer to nodal mesh
 *----------------------------------------------------------------------------*/

void
fvm_writer_export_nodal(fvm_writer_t        *this_writer,
                        const fvm_nodal_t   *mesh)
{
  cs_timer_t  t0, t1;

  fvm_writer_export_nodal_t  *export_nodal_func = nullptr;

  assert(this_writer != nullptr);
  assert(this_writer->format != nullptr);

  void  *format_writer = _find_or_add_format_writer(this_writer, mesh);

  t0 = cs_timer_time();

  export_nodal_func = this_writer->format->export_nodal_func;

  if (export_nodal_func != nullptr) {
    cs_fp_exception_disable_trap();
    export_nodal_func(format_writer, mesh);
    cs_fp_exception_restore_trap();
  }

  t1 = cs_timer_time();

  cs_timer_counter_add_diff(&(this_writer->mesh_time), &t0, &t1);
}

/*----------------------------------------------------------------------------
 * Export field associated with a nodal mesh.
 *
 * Assigning a negative value to the time step indicates a time-independent
 * field (in which case the time_value argument is unused).
 *
 * parameters:
 *   this_writer      <-- pointer to mesh and field output writer
 *   mesh             <-- pointer to associated nodal mesh structure
 *   name             <-- variable name
 *   location         <-- variable definition location (nodes or elements)
 *   dimension        <-- variable dimension (0: constant, 1: scalar,
 *                        3: vector, 6: sym. tensor, 9: asym. tensor)
 *   interlace        <-- indicates if variable in memory is interlaced
 *   n_parent_lists   <-- indicates if variable values are to be obtained
 *                        directly through the local entity index (when 0) or
 *                        through the parent entity numbers (when 1 or more)
 *   parent_num_shift <-- parent number to value array index shifts;
 *                        size: n_parent_lists
 *   datatype         <-- indicates the data type of (source) field values
 *   time_step        <-- number of the current time step
 *   time_value       <-- associated time value
 *   field_values     <-- array of associated field value arrays
 *----------------------------------------------------------------------------*/

void
fvm_writer_export_field(fvm_writer_t                 *this_writer,
                        const fvm_nodal_t            *mesh,
                        const char                   *name,
                        fvm_writer_var_loc_t          location,
                        int                           dimension,
                        cs_interlace_t                interlace,
                        int                           n_parent_lists,
                        const cs_lnum_t               parent_num_shift[],
                        cs_datatype_t                 datatype,
                        int                           time_step,
                        double                        time_value,
                        const void             *const field_values[])
{
  cs_timer_t  t0, t1;

  fvm_writer_export_field_t  *export_field_func = nullptr;

  assert(this_writer != nullptr);
  assert(this_writer->format != nullptr);

  void  *format_writer = _find_or_add_format_writer(this_writer, mesh);

  t0 = cs_timer_time();

  export_field_func = this_writer->format->export_field_func;

  if (export_field_func != nullptr) {
    cs_fp_exception_disable_trap();
    export_field_func(format_writer,
                      mesh,
                      name,
                      location,
                      dimension,
                      interlace,
                      n_parent_lists,
                      parent_num_shift,
                      datatype,
                      time_step,
                      time_value,
                      field_values);

    cs_fp_exception_restore_trap();
  }

  t1 = cs_timer_time();

  cs_timer_counter_add_diff(&(this_writer->field_time), &t0, &t1);
}

/*----------------------------------------------------------------------------
 * Flush files associated with a given writer.
 *
 * parameters:
 *   this_writer      <-- pointer to mesh and field output writer
 *----------------------------------------------------------------------------*/

void
fvm_writer_flush(fvm_writer_t  *this_writer)
{

  fvm_writer_flush_t  *flush_func = nullptr;

  assert(this_writer != nullptr);
  assert(this_writer->format != nullptr);

  flush_func = this_writer->format->flush_func;

  if (flush_func != nullptr) {

    cs_timer_t  t0, t1;

    t0 = cs_timer_time();

    cs_fp_exception_disable_trap();

    for (int i = 0; i < this_writer->n_format_writers; i++)
      flush_func(this_writer->format_writer[i]);

    cs_fp_exception_restore_trap();

    t1 = cs_timer_time();

    cs_timer_counter_add_diff(&(this_writer->flush_time), &t0, &t1);

  }
}

/*----------------------------------------------------------------------------
 * Return accumulated times associated with output for a given writer.
 *
 * parameters:
 *   this_writer <-- pointer to mesh and field output writer
 *   mesh_time   --> Meshes output time (or nullptr)
 *   field_time  --> Fields output time (or nullptr)
 *   flush_time  --> remaining (applying output) time (or nullptr)
 *----------------------------------------------------------------------------*/

void
fvm_writer_get_times(fvm_writer_t        *this_writer,
                     cs_timer_counter_t  *mesh_time,
                     cs_timer_counter_t  *field_time,
                     cs_timer_counter_t  *flush_time)
{
  assert(this_writer != nullptr);

  if (mesh_time != nullptr)
    *mesh_time = this_writer->mesh_time;
  if (field_time != nullptr)
    *field_time = this_writer->field_time;
  if (flush_time != nullptr)
    *flush_time = this_writer->flush_time;
}

/*----------------------------------------------------------------------------*/

END_C_DECLS
